Pipelines are used to transport throughout the nation, a multitude of gas, liquid, and solid materials vital to the domestic and industrial well-being of the economy. Sand, weld slag, water, and other materials are left in a pipeline after the completion of a construction phase which normally consists of welding 20 to 40-foot long sections of steel pipe together to form a pipeline many miles long. During use sand, water, rust, and other debris may collect in a pipeline.
There is a need to remove this debris from the pipeline to effect safe and economic operations. Several methods are currently used to remove debris from pipelines. These include the use of scrapers, high velocity liquid flow and gel plugs. All of these have shortcomings, especially for very long pipelines. The pump capacity and/or volume of fluid needed to remove debris utilizing high velocity flow are often not available. Mechanical scrapers tend to either concentrate the debris in the pipeline to the point of plugging or bypass the debris leaving it in thick beds along the bottom of the pipe. Gels currently used either act much like the mechanical scraper, pushing the debris along the bottom of the pipe, concentrating it and bypassing the thick beds, or like other fluids, require very high velocity to create turbulence in the form of secondary flow currents sufficiently strong to pick up and suspend the debris.
The present invention provides a unique solution to the removal of loose and loosely adhering rust, silt, sand, weld slag, and other debris from pipelines. It is especially applicable both to long pipelines and short pipelines which contain a large quantity of debris distributed throughout.